RD6.1 | Patient Preparation for Imaging — Glossary

A fluid-filled or solid path (e.g. a full bladder or fasted gallbladder) that allows ultrasound waves to reach the target organ without being scattered by gas or bone, improving image quality.

Atomic Energy Regulatory Board — India's statutory radiation-safety regulator (Atomic Energy Act 1962), whose safety codes require clinical justification and dose minimisation for diagnostic ionising procedures.

Cleansing of the colon by low-residue diet, laxatives and/or a cleansing enema before a barium enema (or some abdominal studies) so residual faeces do not obscure or mimic mucosal lesions.

An acute decline in renal function occurring within 48–72 hours of iodinated contrast, most likely in patients with pre-existing renal impairment (eGFR <30 highest risk); minimised by hydration and avoiding contrast where alternatives exist.

A calculated measure of kidney function (mL/min/1.73 m²) used to screen patients before contrast; iodinated-contrast risk rises markedly below 30 and the metformin-withholding rule applies below 60.

Abstaining from food (water and essential medicines usually allowed) for 4–6 hours before an abdominal ultrasound so the gallbladder distends with bile and overlying bowel gas is reduced, enabling assessment of stones and wall thickness.

Drinking water and not voiding before a transabdominal pelvic or early obstetric ultrasound; the distended bladder displaces bowel and provides an acoustic window to the pelvic organs.

A gadolinium-based contrast agent used in MRI; its principal safety concern is nephrogenic systemic fibrosis in severe renal impairment, so eGFR is screened and gadolinium is avoided or restricted to macrocyclic agents at eGFR <30.

Exclusion of a ferromagnetic metal fragment in the eye (by history and, where indicated, orbital X-ray) before MRI, especially in metal-grinding/welding workers, because the magnet could move the fragment and cause injury.

An iodine-based, renally excreted contrast agent used in CT, IVU and fluoroscopy to increase X-ray attenuation in perfused tissues; its main safety concerns are contrast-associated AKI, allergic reactions, and the metformin interaction.

Stopping metformin from the time of iodinated contrast and for 48 hours afterward in patients with eGFR <60 (or large contrast volume), resuming only after renal function is confirmed stable, to prevent metformin accumulation and lactic acidosis if CA-AKI occurs.

A mandatory questionnaire and check, performed because the MRI magnet is always on, that identifies ferromagnetic objects and implants (pacemakers/ICDs, cochlear implants, aneurysm clips, intra-ocular metal) before a patient enters the scanner.

An implanted device certified as safe for MRI only under specified conditions (field strength, programming, monitoring); distinct from MRI-safe, and the reason an unverified pacemaker or implant is a STOP.

A rare, disabling fibrosing disorder of skin and internal organs linked to gadolinium exposure in patients with severe renal failure; the reason eGFR is checked before MRI contrast.

The set of procedure-specific instructions and safety checks (fasting, bladder filling, bowel preparation, medication adjustment, contrast and device screening) carried out before an imaging examination to ensure a diagnostic and safe study.

Confirming a woman of reproductive age is not pregnant before any ionising study (X-ray, fluoroscopy, CT, IVU); if pregnant, a non-ionising alternative (ultrasound or MRI) is preferred where it answers the clinical question.

A communication technique in which the patient repeats the key instructions in their own words so the clinician can confirm understanding and correct misunderstandings before they cause a failed or unsafe study.

The two complementary channels for patient counselling required by RD6.1: a legible, language-appropriate written sheet (with date, time, location, contact) plus spoken counselling that allows teach-back confirmation of understanding.